Sand cooler



Dec. 19, 1967 o. v. MURPHY 3,

SAND COOLER Original Filed Oct. 16, 1964 2 Sheets-Sheet 1 ATTORNEYS Dec. 19, 1967 o. v. MURPHY SAND COOLER Original Filed Oct. 16, 1964 o 6 68 ..v a

7 I. y m 78 2 Sheets-Sheet 2 [\VENTOR.

United States Patent 3,358,380 SAND COOLER Oscar V. Murphy, Newaygo, Mich, assiguor to Newaygo Engineering Company, Newaygo, Mich, a corporation of Michigan Continuation of application Ser. No. 404,447, Oct. 16, 1964. This application Mar. 30, 1966, Ser. No. 544,651

Claims. (Cl. 34-20) This application is a continuation of application Ser. No. 404,447, filed Oct. 16, 1964, now abandoned.

This invention relates to apparatus for cooling foundry sand, and more particularly to recirculating foundry sand cooling apparatus providing variable, controlled discharge with constant cooling and aerating.

Modern foundry methods require forced sand cooling prior to re-use for eflicient operation. Several sand cooling mechanisms hve been devised heretofore. These usually constitute reciprocating oscillatory mechanism. Some assume the form of an elongated double trough or screen. Others constitute a sand cascade through cooling air flowing in a reverse direction past the falling sand.

These prior units are characterized by a narrow range of sand output if they are to operate efficiently. The amount of cooled sand output per unit of time is equal to the input per unit of time, so that changing demands for sand cannot be readily met.

Additionally, those prior units which are practical enough to find commercial acceptance assume a tremendous amount of space in the foundry, often extending 40 to 60 feet in length. Some require elaborate sand distributing mechanisms from a hopper to a reciprocating support, and require elaborate reciprocating or oscillating mechanism.

It is therefore an object of this invention to provide a unique sand cooling apparatus having a completely variable output of cooled sand to be widely varied as needed to supply instantaneous demand Without requiring a corresponding change of said input. Actually the general inflow rate is automatically governed to prevent excess sand in the apparatus as the output is varied. A substantial amount of cooled sand is immediately available to satisfy a substantial increase in demand at any time, since (1) the cooling and aerating is continuous even when demand is low and output is cut down, and (2) large quantities of sand can be discharged quickly from recirculating means. There is, moreover, no reciprocating mechanism with its concomitant vibration and noise.

Another object of this invention is to provide recirculating, constant supply, sand cooling apparatus of variable output and reserve supply of cool sand, that assumes a relatively small amount of space in comparison with prior types. By way of contrast the novel device of about in diameter is equivalent in output to a prior type unit of about 5' width and 50-60 length. The small unit does not cause dust problems since it is easily vented for discharge of dust. It is smooth and quiet in operation. It can be mounted directly beneath an overhead main storage hopper and is capable of handling large input quantities without being choked.

These and several other objects of this invention will become apparent upon studying the following specification in conjunction with the drawings in which:

FIG. 1 is a side elevational view of the novel apparatus;

FIG. 2 is an enlarged sectional view of the apparatus taken on plane II-II of FIG. 1;

FIG. 3 is a sectional elevational view of the apparatus taken on plane III-III of FIG. 2; and

FIG. 4 is an enlarged fragmentary sectional view of one of the cooling air outlet ports in the apparatus.

Referring now specifically to the drawings, the complete sand cooling apparatus 10 is shown mounted beneath a main, conventional, overhead sand hopper 12. The assembly 10 includes a distributing hopper subassembly 14, a cooling platform sub-assembly 16, a forced air supply sub-assembly 18-, an aerator sub-assembly 2%), a drive sub-assembly 22 and a discharge sub-assembly 24.

The distributing hopper sub-assembly 14 basically comprises a generally cylindrical, vertically oriented chamber 30, having an open bottom. Around the lower peripheral edge of the distributing hopper is a plurality of outlet portions 32 allowing the outflow of sand radially outwardly on the disc sub-assembly. The upper end of the distributing hopper includes a suitable connecting means 34 for mounting the distributing hopper to the base of an overhead main hopper 12. The distributor hopper includes a plurality of radial inwardly projecting vertical flanges 15 to cause disruption of the sand clinging to the walls as the disc rotates in a manner to be described hereinafter.

This distributing hopper is positioned centrally on a circular disc 36 substantially larger in diameter than the distributor. This disc comprises a support platform for the sand, both under the distributor 14 and also around the distributor for sand being cooled. The central portion of this disc under the distributor is of solid non-perforated construction. The annular portion around the distributor includes an annulus of hundreds of spaced air ports 38. Each of these vent holes or air ports comprises a vertically oriented elongated orifice as shown in FIG. 4. It is found that optimum cooling of the sand occurs when the upper end 38a of each port 38 is approximately inch in diameter, and the lower portion 38b is about 4 inch in diameter. Preferably, the vents are arranged in severalconcentric rings, with the vents generally radially aligned. The angular displacement between each radial series of holes in a radial line is approximately 2%. These spaced holes effect a complete annular cooling ring zone through which the sand must pass as it travels from the center of the disc to the edge of the disc for removal.

Mounted around the periphery of this disc, and extending upwardly therefrom, is a peripheral housing skirt 40. This housing skirt is attached to and supported by distributor 14, and thus hopper 12, by connecting it to suitable radial support plates 42, 44, 46, 47, 49, and 51. This housing also preferably includes an annular cover 48 having a pair of vent outlets 50 and 52 communicating with suitable venting ducts (not shown). Therefore, dust is readily controlled and passed out through the venting means for filtering.

Fixedly supported to this housing is a pair of aerator units 20 and 20a positioned opposite each other above the annular portion of the circular disc platform. Each includes a rotatable shaft 60 supported at its ends by a pair of pillow blocks 62 and 64 and driven by a belt pulley connection. This drive connection is made by extending the end of shaft 60 out through the housing (as illustrated in FIG. 3), and attaching a pulley 66 to this extended end. Pulley 66 is driven by a belt 68 from pulley 79, which is operably mounted to the shaft of an electrical motor '72. The motor is supported outside of, and on top housing 46. The pillow blocks are suspended on a pair of mounts 76 and '78, which are in turn secured to vertical panel 46 and overhead cover 48.

Since the second aerator unit is exactly the same in construction, it will not be described in detail.

Each of the aerator shafts includes a plurality of radially projecting paddles 80. These paddles have a controlled pitch as illustrated in FIG. 2. The paddles are provided with a pitch to cause the sand to be moved radially outwardly across the disc as the paddles rotate. Thus the paddles not only lift the sand and break up pieces to create a flowable characteristic in the sand, but also gradually move it from the center of the disc to the outer periphery in a controlled fashion over the enclosing through a conduit in cooling zone. It will'benoted that the four inner paddles cause the sand to be pushed radially outwardly over the cooling zone area, while the two outermost paddles of each aerator tend to push a proportion of the sand back onto the cooling zone to prevent excessive build-up at the outer periphery of the disc.

In addition to the air cooling, preferably water spray, evaporative cooling is also employed by mounting an outlet nozzle 61 radially near distributor 14, i.e., near the paddles of the first aerator to spray the sand before it passes thereunder. Hence, the aerating and advancing paddles also constitute blenders. The amount of water added is regulated according to the cooling needed, as

determined by a suitable temperature detector such as a thermocouple 63 located above the disc to contact the sand, upstream of the water nozzle 61.

Mounted to the base of the disc, on the bottom side thereof, is an annular housing forming an annular plenum chamber 90. This plenum chamber communicates with all of the openings 38 to provide compressed air thereto. The plenum chamber has a gradually varying cross section, with a greater height and greater cross sectional area immediately adjacent each of the pair of blowers 92 and 94, and tapering off to a smaller cross sectional area and smaller height at locations spaced intermediate these blowers, i.e., at 90' in FIG. 1. The blowers 92 and 94 are driven through 'belt connections by electrical motors 96 and 98, respectively, to supply compressed air to the plenum chamber. Other equivalent compressed air sources may be used, e.g., an external source not mounted to rotate, and communicating to the plenum chamber the center post assembly.

The blowers and their drive motors are operably supported on generally U-shaped brackets 1G0 and 102. The upper ends of the legs of each U are fixedly attached to the bottom side of disc 36. The electrical connections to these motors are made through flexible conduits 106 and 168 which extend radially inwardly to the central spindle shaft 112, and down through this hollow shaft. A plurality of electrical brushes 114, cooperating with armatures at the lower end of this shaft, provide electrical connection from a fixed electrical power source to the motors 96 and 98 when they rotate with the disc.

The disc and the aerators rotate beneath the stationary distributing hopper 30 while air is forced up through the openings from the blowers through the plenum chamber. Disc 36 is attached to a large, horizontally oriented ring gear 120 through a collar connection 122. This ring gear is rotatably mounted around an annular bearing 124 and on a thrust bearing 126 between it and a lower fixed support stand 128.-This support stand is bolted to mounting base 130 supported by I-beams 131.

This base 130 also houses a drive motor 132 connected through coupling 134 to a gear box 136. The output shaft 139 of this gear box is in turn connected through a coupling 138 to a driven shaft 141 supported in bearing 140. A pinion spur gear 142 is attached to shaft 141. Bearing 140 is supported on an L-shaped mount 144 in a position so that pinion 142 engages with the peripheral teeth of ring gear 120. Operation of the motor therefore rotates the ring gear, which in turn rotates shaft 112 and disc 36, along with blowers 92 and 94 and the annular plenum chamber.

A sand discharge opening 41 is provided in the peripheral apron 40 (FIGS. 1 and 2) to allow cooled aerated sand to be discharged as desired. The discharge is regulated by a diagonally oriented strike off plow. The plow 25 forms the major component of the discharge subassembly 24. It is pivotally mounted on support 27 to have a fraction of an inch clearance from the surface of disc 36. Regulation of discharge is achieved by pivoting the plow with an adjustor in the form of a screw shaft and collar 29, or the equivalent. The plow moves from the deep position shown to a shallow position.

Preferably mounted behind the plow is a wiper blade 31 with a resilient rubber edge. This wiper is mounted on rod 33 which is pivotally supported on a horizontal bearing 35 attached to plate 44. The wiper rests upon and rides over the disc edge area to clean sand therefrom that has not been plowed off. This prevents the sand from dribbling off all around the unit as the disc rotates.

Operation With installation, distributor 30 is attached to the bottom of a conventional overhead hopper 12, using connector 34.

The electrical motors are electrically connected to a suitable outlet. Motor 132 drives gear box 136 and pinion 142 to rotate ring gear 120. This causes the disc, the plenum chamber and the two blowers to. rotate constantly.

Likewise, electrical connection made to brushes 114 and conduits 106 and 108 to motors 96 and 98 causes blowers 92 and 94 to exert apositive air pressure on plenum chamber 90, and thus out the ports 34. This creates an annular zone of cooling through which the sand must pass. Motor 72 and its counterpart are actu; ated to'drive the aerators.

Sand from hopper 12 is then allowed to be dumped into distributor 30. Since this distributor is stationary and the disc below it rotates, the sand moves down through the bottom of the distributor, radially out gate portions 32 onto the disc. The pressure of the sand and the centrifugal force of the rotating disc causes it to move slowly outwardly beneath the aerator blades. The blades, because of their angular pitch, move the sand gradually outwardly across the cooling zone over the ports, while breaking up chunks and elevating the sand. The air blown through the ports passes through the sand to hold it in suspension above the cooling zone as the sand is passed over it. The sand becomes granular and fiowa-ble. Excessive build-up at the periphery of the disc is prevented by slight back treading action of the outermost aerator blades in a controlled manner.

The sand is constantly recirculated, cooled, and aerated until needed. As the sand is needed, plow 24 is pivoted across the disc to divert the sand off the side of the outer periphery of the disc into a suitable re-ceptacleQThe plow 7 can be shifted to take off any desired quantity of sand up to the maximum output of the mechanism. Alternatively, the output rate may be out down to practically nil while still allowing the operation to continue. When the disc builds up a certain amount of reserve sand, the sand simply does not flow out of the distributor outlets until the level of sand decreases. The unit achieves self-regulation with complete dependability and versatility of operation. It never chokes up. V

The apparatus is symmetrical and balanced to enable simple rotational mounting and power operation with relatively small motors. Even though the weight of sand loaded is very great, still the unit is smooth in operation and free of vibration and pounding. All of the sand is treated the same. All must pass the cooling zone and aerators before discharge.

Various advantages additional to those specifically recited herein will readily occur to those having ordinary skill in the field. Also, certain minor structural modifications can conceivably be made in the preferred form of the apparatus illustrated without departing from the scope of the inventive concept taught. Therefore, these modified structures, if within the inventive concept, are deemed to be part of this invention, which is to be limited only by the scope of the appended claims and the reasonably equivalent structures to those defined therein.

I claim:

1. Sand cooling apparatus comprising: a rotatablymounted, perforated disc; air supply means to the perforations of said disc; said perforations being oriented upwardly to blow through and suspend recirculated sand on said disc; sand supply and distributing means above said disc; sand agitating and aerating means adjacent said disc to loosen the recirculating sand; and sand discharge means adjacent a portion of said disc, displaced from said sand supply and distributing means with said cooling Zone and said agitating and aerating means therebetween.

2. Sand cooling apparatus comprising: a rotatablymounted, planar, powered disc; sand supply means above the center of said disc; a large number of upwardly directed ports arranged in an annulus in said disc to vent cooling air into sand recirculated on said disc and form an annular cooling zone between the center of said disc and the outer periphery thereof; plenum chamber means and air supply means beneath said disc and communicant with said ports to supply air and form said cooling Zone; sand aerating means above said disc; and sand removal means adjacent the periphery of said disc for cooled recirculated sand, whereby hot sand from said supply means must pass through said cooling zone and aerating means in its recirculating path to its removal location at the disc periphery.

3. A foundry cooling apparatus comprising: sand distributing means; a circular platform including a central portion beneath said distributing means and an annular portion extending beyond the periphery of said distributing means; said annular portion including an annular pattern of cooling air ports arranged therearound and oriented upwardly through said platform; a plenum chamber beneath said ports and communicant therewith; blower means communicant with said plenum chamber to force air therethrough and out said ports; aerator means mounted above said annular portion to aerate sand on said annular portion; mounting means rotatably supporting said platform, plenum chamber, and blower means; and powered rotatable drive means operably connected to said mounting means to rotate said platform while sand is flowing from said distributing means, radially outwardly on said platform over said ports, and past said aerator means; and take 01? means adjacent said annular platform portion to remove recirculating, cooled sand as needed.

4. The apparatus in claim 3 wherein said plenum chamber is annular in configuration and said blower means comprises a pair of oppositely positioned blowers, and

wherein sand aerator means comprises a pair of oppositely positioned rotating paddle assemblies achieving a symmetrical balanced apparatus.

5. A foundry sand cooling apparatus comprising: a vertical, cylindrical, fixed sand distributing hopper means; said distributing means having an open bottom and peripheral outlets in its lower edge; a circular platform beneath said distributing means including a central solid portion beneath the open bottom of said distributing means and an annular portion extending beyond the periphery of said distributing means; said annular portion having cooling air ports arranged therearound in an annulus and each oriented upwardly through said platform; an annular plenum chamber attached to the bottom side of said platform beneath said ports and communicant therewith; blower means attached to and communicant with said plenum chamber to force air therethrough and out said ports; said annular plenum chamber having a larger vertical depth and cross sectional area adjacent said blower means, and tapering to a lesser vertical depth and cross sectional area displaced therefrom; aerator paddle means mounted above said annular portion and rotatably supported to aerate and radially move sand across said annular portion; drive means operably connected to said aerator means; spindle mounting means rotatably supporting said platform, plenum chamber, and blower means; and powered rotatable drive means operably connected to said mounting means to rotate said platform while sand is flowing from said distributing means, over said ports, and past said aerator means; and shiftable, discharge plow means above and adjacent a peripheral portion of the outer edge of said annular platform portion to remove recirculating, cooled sand.

35 References Cited UNITED STATES PATENTS 56,868 7/1866 Tommar 34-59 1,251,573 1/1918 Provost 34-59 2,861,353 11/1958 Lellep 34-20 3,175,686 3/1965 Rieth 34-8 WILLIAM J. WYE, Primary Examiner. 

1. SAND COOLING APPARATUS COMPRISING: A ROTATABLYMOUNTED, PERFORATED DISC; AIR SUPPLY MEANS TO THE PERFORATIONS OF SAID DISC; SAID PERFORATIONS BEING ORIENTED UPWARDLY TO BLOW THROUGH AND SUSPEND RECIRCULATED SAND ON SAID DISC; SAID SUPPLY AND DISTRIBUTING MEANS ABOVE SAID DISC; SAID AGITATING AND AERATING MEANS ADJACENT SAID DISC TO LOOSEN THE RECIRCULATING SAND; AND SAND DISCHARGE MEANS ADJACENT A PORTION OF SAID DISC, DISPLACED FROM SAID SAND 